7. If superman in space throws a boulder with 10 times as much mass as himself, and the boulder leaves his hands at 100 m/s, how fast does superman recoil?
A) 1000 m/s.
B) The same speed, 100 m/s.
C) 10 m/s.
D) None of these are correct.
principles of physics - Damon, Sunday, February 19, 2012 at 6:03pm
see my replies to these questions a bit further down.